Biomass Technologies: Overview and Future Trends

Small Wood 2004Sacramento, CA

May 20, 2004

John Scahill

Thinning ResiduesThinning ResiduesWood chipsWood chipsUrban Wood wasteUrban Wood waste

palletspalletscrate discardscrate discardswood yard trimmingswood yard trimmings

Corn stoverCorn stoverRice hullsRice hullsSugarcane bagasseSugarcane bagasseAnimal Animal biosolidsbiosolids

Hybrid poplarHybrid poplarSwitchgrassSwitchgrassWillowWillow

Forest Wood Residues Agricultural Residues Energy Crops

Biomass FeedstocksBiomass Feedstocks

O

OO

OH

OH

OH

HOHO

OHO

O

OO

OH

OH

OH

HOHO

OHO

O

OO

OH

OH

OH

HOHO

OHO

O

OO

OH

OH

OH

HOHO

OHO

O

OO

OH

OH

OH

HOHO

OHO

O

OO

OH

OH

OH

HOHO

OHO

O

OO

OH

OH

OH

HOHO

OHO

O

OO

OH

OH

OH

HOHO

OHO

OHO

HO

H3CO

OH

OCH3

OCH3

O

O

O

OH

OCH3

OCH3

H3CO

OO

HO

H3CO

HO

OCH3

OCH3

OHO

HO

H3CO

OH

OCH3

OCH3O

O

OH

OCH3

OCH3

OCH3

OO

O

OH

HO

O

OO

O

OH

HO

OH

OH

OO

O

OH

HO

OH

OH

OO

O

OH

HO

OH

OH

O

OO

OH

OH

OH

HOHO

OHO

O

OO

OH

OH

OH

HOHO

OHO

O

OO

OH

OH

OH

HOHO

OHO

O

OO

OH

OH

OH

HOHO

OHO

O

OO

OH

OH

OH

HOHO

OHO

O

OO

OH

OH

OH

HOHO

OHO

O

OO

OH

OH

OH

HOHO

OHO

O

OO

OH

OH

OH

HOHO

OHO

Biomass Constituents

Lignin: 15-25%Complex aromatic structure

Very high energy content

Hemicellulose: 23-32%

Polymer of 5 & 6 carbon sugar

Cellulose: 38-50%Polymer of glucose, very good

biochemical feedstock

Solid

Gas or Sugars

Power & Liquid Fuels

Biomass Conversion Pathways

Thermal Biological Physical

Combustion Gasification Pyrolysis

Heat Fuel Gases (CO + H2)

Liquids

Pretreatment

Fermentation

Ethanol

Hydrolysis

(Heat & Pressure)

Liquids

No AirPartial airExcess airA/D

CH4

H2

Bio-Chemical Technology

Processeffective for converting

cellulose- and hemicellulose-

into simple sugars

The Biomass Saccharification Process

• Mineral acid gives good hemicellulose sugar yields and high cellulose digestibility

• Sulfuric acid usual choice because of low cost• Requires downstream neutralization and conditioning

• Typical conditions: 100-200oC, 50 to 95% moisture, 0-1% H2SO4

• Some degradation of liberated hemicellulose sugars• Current commercial cellulase enzyme preparations release

glucose, cellobiose, and some xylose.

mineral acid

biomass Stage 1. Pretreatment

Stage 2.Enzymatichydrolysis

glucoseand lignin

celluloseand lignin

hemicellulose sugars and oligomers

NREL’s Enzymatic Hydrolysis Partnerships

3-year Partnerships with Genencor & Novozymes– Enzyme biochemistry and specific activity– Cellulase - cellulose surface interaction– Reduce cost of enzyme production ($0.25/gal)– Reduce risk to investors

-1

+1

+2

-2

cellodextrin

Y82

CBH1 from T. reesei

E1 from A. cellulotiticus

Schematic of an Integrated Biorefinery

Biomass Conversion Pathways

Thermal Biological Physical

Combustion Gasification Pyrolysis

Heat Fuel Gases (CO + H2)

Bio-oil

Pretreatment

Fermentation

Ethanol

Hydrolysis

(Heat & Pressure)

Liquids

No AirPartial airExcess airA/D

CH4

H2

• Rapid heat transfer in the absence of oxygen• Short residence time at temperature (msec)• Thermal cleavage of macropolymer bonds

(lignin, cellulose, hemicellulose) • Liquids (70%), gas (15%), Char (15%)

Pyrolysis Technical Requirements

FLUID BED CATALYTIC

STEAM REFORMING

gascharcoal

Bio-oil Refinery Approach

pyrolytic lignin

bio-oil SEPARATION

H2O

hemicellulose fraction

bio-oil aqueous fraction

phenolic resins fuel additives

extractivescellulose pulp

lignin derivatives

COH2CO2H2O

H2CO2

FRACTIONATION

H2O FOOD PROCESSING

trap grease

TRANSESTERIFICATION

glycerin/lipid fraction

lignocellulosic biomass

plant&animal fats

biodiesel

raw food

processed food

specialty carbons

Shift Conversion & PSA

Shift Conversion & PSA

PyrolysisPyrolysis

Bio-Oil Aqueous Fraction Fluidized Bed Reforming

Gas Composition

0

10

20

30

40

50

60

70

80

0 1000 2000 3000 4000 5000 6000Time, min

Vol

. %

0

5,000

10,000

15,000

20,000

25,000

30,000

35,000

40,000

45,000

Vol

., pp

m

H2

CO2

CO

CH4

Bio-Oil From Pyrolysis

Potential Markets / Products

• Liquid boiler fuel substitute

• Reform to Hydrogen

• Food flavorings / Specialty chemicals

• Phenolic replacements

• Asphalt binders

• Liquid boiler fuel substitute

• Reform to Hydrogen

• Food flavorings / Specialty chemicals

• Phenolic replacements

• Asphalt binders

More than 30 products are made today

from Bio-Oil and process energy

Oriented Strand Boards and Plywood made from Bio-Oil – Phenolic Resins

Biomass Conversion Pathways

Thermal Biological Physical

Combustion Gasification Pyrolysis

Heat (CO + H2)

Synthesis gas

Liquids

Pretreatment

Fermentation

Ethanol

Hydrolysis

(Heat & Pressure)

Liquids

No AirPartial airExcess airA/D

CH4

H2Power and Liquid fuels

Gasification

Air (0.3)O2 (0.3)Steam

Heat

Producer Gas (mol%)

CO 24H2 13CH4 3CO2 8N2 52

(tars & particulate)

Synthesis Gas (mol%)

CO 39H2 20CH4 17C2H2 6CO2 18N2 0

(tars & particulate)

Fuel Gases

Pyrolysis

Reduction

Combustion

Gas, Tar, Water

Ash

Biomass

Air

C + CO2 = 2COC + H2O = CO + H2

C + O2 = CO24H + O2 = 2H2O

Updraft Gasifier

Pyrolysis

Reduction

Combustion

Gas, Tar, Water

Ash

Biomass

Air

C + CO2 = 2COC + H2O = CO + H2

C + O2 = CO24H + O2 = 2H2O

Updraft Gasifier

Freeboard

Fluid Bed

PlenumAir/Steam

Biomass

Ash

Cyclone

Fluid-Bed Gasifier

Freeboard

Fluid Bed

PlenumAir/Steam

Biomass

Ash

Cyclone

Fluid-Bed Gasifier

Secondary

Circulating Fluid-Bed Gasifier

Fly Ash

Bottom Ash

Biomass

Air/Steam

GasifierPrimaryCyclone

CycloneSecondary

Circulating Fluid-Bed Gasifier

Fly Ash

Bottom Ash

Biomass

Air/Steam

GasifierPrimaryCyclone

Cyclone

Fly Ash

Bottom Ash

Biomass

Air/Steam

GasifierPrimaryCyclone

Cyclone

Biomass

Pyrolysis

Reduction

Combustion

Gas, Tar, Water

AshAir

C + CO2 = 2COC + H2O = CO + H2

C + O2 = CO24H + O2 = 2H2O

Downdraft Gasifier

Biomass

Pyrolysis

Reduction

Combustion

Gas, Tar, Water

AshAir

C + CO2 = 2COC + H2O = CO + H2

C + O2 = CO24H + O2 = 2H2O

Downdraft Gasifier

Biomass

N2 or Steam

Furnace

Char

Recycle Gas

Flue Gas

Entrained Flow Gasifier

Air

Biomass

N2 or Steam

Furnace

Char

Recycle Gas

Flue Gas

Entrained Flow Gasifier

Air

Different Gasifier Designs

Entrained Flow Gasification

CharBurner

Air

Synthesis gas

Gas Slip stream

Flue Gas

Biomass

Steam

850 C

(Steam Reforming)

Staged Gasification

Pyrolysis

Vapors + steam

Synthesis

GasBurnerBurner

850 C

700 C

Biomass + moisture

Pyrolysis Steam Reforming

Carbon Conversion Technologies 2004

General Process DescriptionSyngas-to-Liquids

GasifierGasifier Gas Cleanup and Conditioning

Gas Cleanup and Conditioning

Oxygen

or Steam

coal, natural gas, biomass

• Catalytic tar conversion

• Sulfur scrubbing

• Shift H2/CO ratio

• Particulate removal

• Wet scrubbing

Catalytic reactorCatalytic reactor

Liquid Fuels

75 100 125 150 175 2000

2e+4

4e+4

6e+4

8e+4

1e+5 78

91,92

104 116

128

142 152 166 178

192 216

94

108 202

78 - benzene91,92 - toluene94 - phenol104 - styrene108 - cresol116 - indene128 - naphthalene

142 - methylnaphthalenes152 - acenaphthalene166 - flourene178 - anthracene/phenanthrene192 - methylanthracene?202 - pyrene/flouranthene216 - benzo(a)flourene

Averaged mass spectrum (TMBMS) of tars from indirect wood gasification

NREL TCPDU Product Gas Tar Composition

Tars can be reformed to additional H2 + CO

• Nickel catalysts

• 850 ° - 900° C

Tars can be reformed to additional H2 + CO

• Nickel catalysts

• 850 ° - 900° C

Source: VTT Research C

enter, Finland

Syngas Conditioning

Gasification ReactionsGasification Reactions

C + CO2 2 CO (Boudouard)

CO + H2O CO2 + H2 (Water gas shift)

800° - 850° C

Control of temperature and steam content adjusts H2 / CO ratio in Syngas

Gas Cleanup RequirementsFor Fischer-Tropsch gas-to-liquids

Below dew point < 1 ppmvTars

Essentially completelySoot, dust, ash

< 10 ppbvHCl

< 1 ppmvH2S, NH3, HCNRemoval levelImpurity

Source: H. Boerrigter et al, October 2002

Biomass

Clean Syngas

750-3800

200-420

Cu-ZnCu-CoOthers

1.0-1.4

PSITemp °C

CatalystH2/CO

PSITemp °C

CatalystH2/CO

1450< 250Cu-ZnO2.3

PSITemp °C

CatalystH2/CO

370240Co-K2.0

340340Fe2.0

Ethanol

Mixed Alcohols

Methanol

DME

Zeolite Cat.

Gasoline

Gasoline -Wax

Diesel -WaxHydrocracking

Gasoline/diesel

Feed Prep

Gasification

Gas

Cleanup

Syngas to Liquid Fuel Options

F-T Liquids

Source: NREL/TP 510-34929

Gas to Liquids Process Issues

H2/CO Ratio

Liquid Product

Pressure letdown

Heat

Heat

Catalyst Reactor

Temp - Press

Recycle Compressor

Conversion 15-40%

Selectivity to Desired Product

• Syngas Conditioning (cleanup)

• Gas recycle costs

• Heat removal (highly exothermic)

• Syngas Conditioning (cleanup)

• Gas recycle costs

• Heat removal (highly exothermic)

Tail gas

Liquid Fuel Properties

< 1 (ppm)Sulfur

< 0.01 (mass %)

Polycyclic aromatics

< 3 (vol. %)Total aromatics

> 70 (conventional 45-50)

Cetane

2Hexanol & higher3Pentanol5Butanol15Propanol

45-75Ethanol5-30MethanolWt%Type

F-T Diesel (high quality) Mixed Alcohols

Source: www.sasol.com

Source: Taylor (2002)

Commercial History of Gas-to-Liquids

• SASOL (South Africa) 1955– Coal CH4 hydrocarbon fuels/chemicals

• Shell (Malaysia) 1993, 12,000 bbl/day– Natural gas syngas gasoline

• BP / Davy Process Tech (Alaska) 2002– Stranded CH4 short chain hydrocarbons– Compact, modular design– Small barge mounted plants under development

• Syntroleum (Australia) under construction/shakedown

Economic ComparisonsBiomass to F-T Liquids vs. Electricity

$32Levelized COE $0.07 / kWh (2)

$9 - $18Purchase agreement $0.02-.04 / kWh

(2) 455 kWh/ton (combustion-steam

turbine)

$108$1.14+.21=$1.35/gal (3)(4)(1) 79.8 gal/ton

$/ton biomass

ValueYield

50 wt% conversion biomass to syngas

1. 10,000 ft3 syngas/bbl syncrude (Hydrocarbon Processing Feb 2003)

2. 455 kWh/g ton biomass, $.07/kWh COE (McNeil Technologies Nov 2003)

3. EIA current diesel production cost (May 9, 2004)

4. EIA estimate of FT diesel premium value - $9/bbl

50 wt% conversion biomass to syngas

1. 10,000 ft3 syngas/bbl syncrude (Hydrocarbon Processing Feb 2003)

2. 455 kWh/g ton biomass, $.07/kWh COE (McNeil Technologies Nov 2003)

3. EIA current diesel production cost (May 9, 2004)

4. EIA estimate of FT diesel premium value - $9/bbl

Basis:

Biomass Conversion Pathways

Thermal Biological Physical

Combustion Gasification Pyrolysis

Heat Fuel Gases (CO + H2)

Liquids

Pretreatment

Fermentation

Ethanol

Hydrolysis

(Heat & Pressure)

Liquids

No AirPartial airExcess airA/D

CH4

H2

Biomass Combustion for Heat

• Increasing interest– Industrial parks– Multiple buildings

(district heating)• High natural gas

costsSource: BioEnergy Corp.Nederland, CO

Biomass Power Applications

• Combustion / steam turbine – mature but low efficiency

• Small modular systems - emerging technology

• Gasification combined cycle – under development

Biomass is the only renewable resource that causes problems when it is NOT used!